All of my photos are taken and edited on my smartphone. I have a Sony Xperia and I use free photo editing apps from the Play Store.
Most smartphones these days have excellent cameras and I have to say I love the camera on the Xperia.
As far as editing goes you actually get some pretty good photo editing apps with the Xperia but I have no doubt iPhones and other android phones have similar.
I use Light Effects, Mirror Photo, Camera Effects, Pixlr-o-Matic and Photogrid.
Pixlr-o-Matic Has some good filters and bokeh. Mirror Photo has various mirror effects, filters and frames. Light Effects is where I get various fantasy and flame effects and Camera Effects has some good filters and it’s where I get my stars and planet effects.
There’s so right or wrong way to use these apps. The strength of the end image will depend on the original photo you take. So play around and find your style!
These apps and many more are free so get downloading, see what’s available.